Connect Hip Bone to the Tail of Backbone
Like Sambler eluded to, parent the hip bones to the backbone without being connected.  This is also known as 'Keep Offset'.


Get into Bone Edit mode.
Select Hip_L/Hip_R bone.
Select Backbone.
Hit Ctrl+P and from the menu select Keep Offset.



Here's the result of the above steps, repeated for both hips.